<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        .box_1{
            height: 300px;
            width: 300px;
            background-color: #5c6b77;
            border: 1px solid #ff5777;
        }
        .box2{
            height: 200px;
            width: 200px;
            background-color: #72fa4c;
            border: 1px solid #ff5777;
        }
        .span{
            height: 30px;
            width: 50px;
            background-color: #666666;
        }
    </style>
    <script>
        window.onload=function () {
            document.getElementById('body_').addEventListener('click',eventHandler)
        };
        function eventHandler(event) {
            console.log("时间："+new Date(event.timeStamp)+" 产生事件的节点：" + event.target.id +"  当前节点："+event.currentTarget.id)
        }
    </script>
</head>
<body id="body_">
<div id="box_1" class="box_1">
    <div id="box2" class="box2">
        <span id="span">This is a span.</span>
    </div>
</div>

</body>
</html>